Question

Consider the concentration cell in which the metal ion has a charge of +2, and the solution concentrations are:

dilute solution = 0.015 M

concentrated solution = 1.183 M

What is the predicted Ecell, using the Nernst equation? ____ V

Provide your response to three digits after the decimal.

Answer 1

For concentration cell, cathode and anode are same electrode

So, Eo = 0

Number of electron being transferred in balanced reaction is 2

So, n = 2

If E is positive anode will be the one with lower concentration

we have below equation to be used:

E = Eo - (2.303*RT/nF) log {[M+] at anode/[M+]at cathode}

Here:

2.303*R*T/n

= 2.303*8.314*298.0/F

= 0.0591

So, above expression becomes:

E = Eo - (0.0591/n) log {[M+] at anode/[M+]at cathode}

E = 0 - (0.0591/2) log (0.015/1.183)

E = 5.608*10^-2 V

E = 0.056 V

Answer: 0.056 V